The main advantages of the NEMI symbol assessment method are the simplicity of the assessment and reading the score, one fast look at the pictogram will be enough to have a general information about the environmental impact of a procedure. However, the drawbacks of this method are non-consideration of the amount of chemicals used in the analysis and the waste generated (qualitative rather than quantitative analysis) and the obtained information is general. In addition, the search of each chemical used in the procedure in official lists is inconvenient and time wasting [155 - 157].
An improvement to the NEMI pictogram was proposed by de la Guardia and Armenta [82].
These authors suggested different colors for each of the fields using a three …show more content…
From the total of 100 points, penalty points are subtracted for each negative impact on the environment (Like hazardous chemicals used, waste generation and high energy consumption) where Analytical Eco-Scale = 100 - total penalty points. Figure 6 shows an example of how to calculate the deduced points for each reagent or solvent used by simply counting the number of hazard pictogram present on the chemical container and multiplying it by (1) in case of warning signal and (2) in case of danger signal (Signal word that is found in chemical safety data sheet). While figures 7 and 8 give examples of penalty points used in calculation, the procedure is considered green if the final score is above 75 points, a score between 50 and 75 indicates that it is acceptably green and a score below 50 indicates non-environmentally benign method. The advantages of using eco-scale method are: The amounts of chemicals and waste are calculated semi-quantitavely, it is a simple method with well-defined evaluation criteria, it provides information about environmental impact of analytical procedures in a more quantitative way than NEMI method, the ease of comparison of different analytical procedures and finally, it includes different aspects of environmental impact in its assessment. But, there is one main …show more content…
9.3. Environmental Assessment Tool (EAT)
EAT is a tool used for identification of hazards related to the use of liquid chromatographic mobile phases (Because it focuses on HPLC solvent amount and type) where a score is calculated based on the sum of safety, health, and environmental factors for a given amount of solvent applied during LC analysis, which reflects the overall greenness of the method. The lower the EAT value, the greener the procedure used. The advantage of this tool for assessment is that it is a simple method with a downloadable computer program.
However, the limitation is that the final result of assessment is a single number that gives only general view and does not provide any information about a character of risk.
The score is calculated according to the following equation:
HPLC-EAT= S1m1 + H1m1 + E1m1 + S2m2 + H2m2 + H3m3 + Snmn + Hnmn + EnmnEquation 9
Where; S, H, and E are safety, health and environmental factors, respectively, for n number of solvents, and m is the mass of the solvent (s). From the equation above, it is concluded that the number, amount and hazards of solvents used are the main factors influencing the assessment [157,
An improvement to the NEMI pictogram was proposed by de la Guardia and Armenta [82].
These authors suggested different colors for each of the fields using a three …show more content…
From the total of 100 points, penalty points are subtracted for each negative impact on the environment (Like hazardous chemicals used, waste generation and high energy consumption) where Analytical Eco-Scale = 100 - total penalty points. Figure 6 shows an example of how to calculate the deduced points for each reagent or solvent used by simply counting the number of hazard pictogram present on the chemical container and multiplying it by (1) in case of warning signal and (2) in case of danger signal (Signal word that is found in chemical safety data sheet). While figures 7 and 8 give examples of penalty points used in calculation, the procedure is considered green if the final score is above 75 points, a score between 50 and 75 indicates that it is acceptably green and a score below 50 indicates non-environmentally benign method. The advantages of using eco-scale method are: The amounts of chemicals and waste are calculated semi-quantitavely, it is a simple method with well-defined evaluation criteria, it provides information about environmental impact of analytical procedures in a more quantitative way than NEMI method, the ease of comparison of different analytical procedures and finally, it includes different aspects of environmental impact in its assessment. But, there is one main …show more content…
9.3. Environmental Assessment Tool (EAT)
EAT is a tool used for identification of hazards related to the use of liquid chromatographic mobile phases (Because it focuses on HPLC solvent amount and type) where a score is calculated based on the sum of safety, health, and environmental factors for a given amount of solvent applied during LC analysis, which reflects the overall greenness of the method. The lower the EAT value, the greener the procedure used. The advantage of this tool for assessment is that it is a simple method with a downloadable computer program.
However, the limitation is that the final result of assessment is a single number that gives only general view and does not provide any information about a character of risk.
The score is calculated according to the following equation:
HPLC-EAT= S1m1 + H1m1 + E1m1 + S2m2 + H2m2 + H3m3 + Snmn + Hnmn + EnmnEquation 9
Where; S, H, and E are safety, health and environmental factors, respectively, for n number of solvents, and m is the mass of the solvent (s). From the equation above, it is concluded that the number, amount and hazards of solvents used are the main factors influencing the assessment [157,